Disparities in health outcomes by socioeconomic status (SES) are one of the most pressing public health problems our society faces today. In line with PAR-10-136's interest in multi-level approaches to understanding health disparities, we focus on childhood asthma and investigate factors simultaneously across neighborhood, family, and individual levels; we consider both physical environment and social environment exposures together; and we examine various levels of biological processes (organ systems, cellular, genomic) that drive asthma pathophysiology, all within a single project that seeks to develop a more comprehensive understanding of the causes of asthma disparities. The first aim is to understand how neighborhood, family, and individual-level social factors both shape and are shaped by one another, and how they collectively affect asthma disparities. The second aim is to measure social and physical exposures concurrently in order to explain how they interact to affect asthma disparities. The third aim is to create biologically plausible models for how social contexts contribute to health disparities by characterizing pathways at multiple levels biologicall (organ systems, cellular, genomic) that can explain how social contexts come to affect asthma disparities. This study will recruit a sample of 300 families from varying SES backgrounds who have a child ages 10-18 with persistent asthma. Families will participate in laboratory assessments of individual- and family-level social processes as well as child biological measures. Information on neighborhood characteristics will be linked from geographic information system maps of pollution exposures and maps of the social characteristics of communities created by a research consortium locally. In order to establish the temporal precedence of each of the 'levels' of factors, clinical outcomes will be tracked across a 1 year follow up period via monthly monitoring of symptoms as well as from hospitalization data obtained from provincial health records. Creating models that explain how neighborhood, family, and individual factors simultaneously contribute to asthma disparities is critical for developing a more holistic picture of how social contexts affect disease progression. These models will in turn shape our approaches to interventions. For example, interventions to improve medication adherence may not be effective if they do not acknowledge the broader social factors (e.g., neighborhood and family stress) that affect families' abilities to keep up with medication regimens. Assessing interactive effects between factors will also allow us to identify specific conditions under which potential targets of intervention would make the biggest differences in mitigating the pathophysiological processes underlying asthma. The overall goal of this project is to develop a more sophisticated understanding of why asthma disparities by SES exist and to identify the constellation of factors that would need to be targeted simultaneously in order to effectively alleviate these disparities.